1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Identification of yellow mite resistant lines in early segregating generation of chilli (Capsicum annuum L.)(Department of Plant Breeding and Genetics, College of Agriculture, Vellanikkara, 2025-03-14) Mithun Vasudev; Asish, I EdakkalathurChilli (Capsicum annuum L.), is one of the most important vegetables as well as spice grown in tropical and subtropical regions. However, the productivity of chilli is adversely affected by insect complex especially aphids, thrips and mites. Chemical management of mites are often not encouraged due to negative consequences such as residue in harvested produce, pesticide resistance and various other environmental problems. Development of resistant varieties that utilize plant defence mechanisms is the sustainable solution. In this context, the present study entitled Identification of yellow mite resistant lines in early segregating generations of chilli was carried out during 2024. Previous study conducted at the Department of Plant Breeding and Genetics, Vellanikkara had identified three moderately mite resistant chilli hybrids viz., Anugraha x 417, Anugraha x 445, and 451 x 445. F2 and F3 generations of above three crosses along with their parents served as the experimental material for the present study. Varieties viz., Anugraha and Ujwala were used as checks. F2 generation of the above three hybrids each with a population size of 200 plants were raised for evaluation. Hundred plants belonging to F2 generation of each cross were raised in the open field condition and the remaining 100 plants under the polyhouse. Parents involved in the above crosses were similar in qualitative characters such as hypocotyl colour, cotyledonous leaf colour, stem colour, nodal anthocyanin, leaf colour, leaf shape, flower position, corolla colour, anther lobe colour, filament colour, stigma exertion, calyx pigmentation, anthocyanin spots on fruits, fruit colour at intermediate stage, fruit shape, mature fruit colour, fruit blossom end appendage, fruit cross-section corrugation, fruit surface, seed colour and seed surface. So, there was no variation for these traits in the F2 generation. Corolla shape and fruit shape at the blossom end segregated in 9:7 ratio in the F2 generation revealing complementary gene interaction involving two genes. Segregating lines from the F2 populations were superior to checks and parental lines in terms of early flowering, early fruiting, fruit length, fruit girth, fruit weight, number of fruits per plant and yield per plant. F2 population raised in the open field condition had more variability than that under the polyhouse. High heritability coupled with high genetic advance as percentage of the mean were recorded for days to flowering, fruit girth, fruit weight, number of fruits per plant and yield per plant suggesting the predominance of additive gene action in inheritance of these traits. Under polyhouse conditions, days to flowering and days to fruiting as well as fruit length and girth under open field conditions exhibited leptokurtic distributions. Conversely, under open field conditions, days to flowering and days to fruiting along with fruit length and girth under polyhouse conditions exhibited platykurtic distributions. Most of the traits except days to flowering and days to fruiting, expressed positively skewed distribution revealing complementary gene action in the expression of those traits. Artificial release of mites was carried out at 30 days after transplanting (DAT) by leaf clipping and scoring of mite resistance was done according to Niles (1980), and Latha and Hanumanthraya (2018) at 45, 60 and 75 DAT. Percentage of leaves exhibiting downward curling symptoms (PLDC) ranged from 4.13 to 83.80 in the F2 generation, whereas it was in the range of 24.37 to 65.84 in the checks. Among the segregating generation, PLDC ranged from 9.01 to 80.79 under the polyhouse condition, whereas it was in the range of 4.13 to 83.80 in the open field. There was no immune genotype in the F2 generation. Based on the PLDC, there were 106 resistant, 281 moderately resistant, 201 susceptible, and five highly susceptible genotypes. Mite population was recorded from the resistant and moderately resistant genotypes at 75 DAT. Total number of eggs and active stages of mites ranged from zero to 13.25/cm2 on leaves of resistant genotypes under the polyhouse. Resistant and moderately resistant F2 plants were selected and forwarded to F3 generation as progeny rows. In the F3 generation, PLDC varied between 3.33 and 89.47. There were significant differences between the progeny rows with respect to PLDC. Based on the PLDC at 75 DAT, selection was carried out within and between the progeny rows. Out of 1260 genotypes in the F3 generation, 129 were resistant and 390 were moderately resistant at 75 DAT. Total number of mite eggs and active stages on resistant plants ranged from zero to 55.00/cm2 at 75 DAT. The resistant lines identified from this study could be used as new varieties or as parents in the hybridization programme after attaining homozygosity.Item Evaluation of Chilli (Capsicum annuum L.) genotypes for yield, bacterial wilt and leaf curl virus incidence(Department of Vegetable Science, College of Agriculture , Vellanikkara, 2024-05-21) Suvarna, K; Anitha, PChilli is one of the important vegetable spice cultivated worldwide and is commonly referred to as red pepper or hot pepper. It is a crucial commercial crop utilized as a vegetable, spice, condiment and culinary flavour enhancer. Chilli is mainly used as culinary supplement to add flavour, colour and pungency. Chilli is an abundant source of vitamin A and C. Capsaicin and its related compounds present in the placental tissue of its fruits is used in pain relieve balms and vapour rubs. The green fruits of chilli stand out as one of the most plentiful sources of antioxidants. Despite its considerable nutritional value, widespread acceptance among consumers and extensive genetic diversity, achieving optimal productivity in chilli production remains a challenge due to lack of high-yielding and disease-resistant varieties or hybrids. In addition, diseases like chilli leaf curl virus and bacterial wilt are the most two important diseases affecting chilli production. In this context, the current study was initiated with the objective of assessment of morphological traits of chilli genotypes for yield to identify high yielding ones and to simultaneously evaluate these genotypes against bacterial wilt and leaf curl virus incidence. The present study was conducted in the Department of Vegetable Science, College of Agriculture, Vellanikkara during January 2023 to May 2023, using 31 chilli genotypes. The analysis of variance among the 31 genotypes of chilli revealed significant variations across all the traits. Genetic parameters such as Genotypic Coefficient of Variation (GCV), Phenotypic Coefficient of Variation (PCV), heritability and Genetic Advance (GA) were computed to assess the extent of variability. High GCV and PCV were exhibited by the characters like plant height, fruits per plant, average fresh fruit weight, average dry fruit weight, fruit length, fruit girth, pedicel- fruit ratio, yield per plant, bacterial wilt incidence, incidence of leaf curl virus, oleoresin content, capsaicin content, ascorbic acid content. The results indicated that the presence of a broad genetic base which will be useful in further selection. High heritability coupled with high genetic advance was reported in most of the morphological and quality characters indicating that these characters are under the influence of additive gene action. Therefore, it is feasible to apply direct selection for improving these traits. Correlation studies indicated that fruit yield per plant was significantly and positively correlated with plant height, primary branches per plant, fruits per plant, average fresh fruit weight, average dry fruit weight, fruit length, pedicel length, oleoresin content, capsaicin content and ascorbic acid content. Interrelationships among plant traits is crucial for enhancing both yield and quality. Hence, simultaneous selection for these characters would be advantageous for enhancing chilli yield. Path coefficient analysis among yield and its constituent traits indicated that the fruits per plant, average fresh fruit weight, days to harvest, pedicel length, fruit girth and plant height showed direct positive influence on yield. Path analysis reveals whether the correlation between yield-related traits and yield is having direct effect, in which case direct selection for improvement is possible. From the present study, based on the path coefficient and correlation results the genotypes CA 1, CA 3, CA 6 and Ujwala were recognized as promising or advantageous. The 31 chilli genotypes were categorized into eleven clusters using Mahalanobis D2 statistic. Cluster I contained the largest number of genotypes (21), followed by cluster II, cluster III, cluster IV, cluster V, cluster VI, cluster VII, cluster VIII, cluster IX, cluster X and cluster XI which had one genotype each. The intra-cluster distance was the highest in cluster I, while the inter-cluster distance was the greatest between cluster IV and cluster IX. Hence, selecting genotypes for hybridization or developing hybrids, genotypes from these two clusters should be prioritized. The selection index for chilli was established based on the characters including fruit yield per plant, fruits per plant, average fresh fruit weight, incidence of leaf curl virus and bacterial wilt incidence. Among the genotypes evaluated, CA 3, CA 6, CA 1 and Ujjwala were identified as the top performers. Notably, genotypes CA 3, CA 6 and CA 1 exhibited superior performance in terms of yield and leaf curl virus resistance when compared to Ujwala.Item Impact of seed priming on psychological and biochemical mechanisms under water stress condition in chilli (Capsicum annuum L.)(Department of Seed Science and Technology, College of Agriculture , Vellayani, 2023-12-16) Madamsetty Phani Kumar; Beena, RA study entitled “Impact of seed priming on physiological and biochemical mechanisms under water stress condition in chilli (Capsicum annuum L)” was undertaken with the objective assessment of the effect of seed priming on physiological and biochemical mechanisms and yield components under water stress condition in chilli. For both experiments I & II seeds of the chilli variety ‘Vellayani Anugraha’ were primed with 2.5% potassium nitrate (KNO3), 3% silicon dioxide (SiO2), and unprimed were soaked in distilled water for 24 hours and subjected to control and water stress levels at flowering stage. The first experiment was carried out in a factorial completely randomized design (FCRD) with the first factor being stress levels and the second-factor being priming agents using different solutions replicated thrice. The seeds primed with 2.5% KNO3, 3% SiO2, and unprimed seed treatments were sown in protrays. Seedlings were transplanted to pots 35 days after sowing (DAS), irrigation, and other cultural practices were followed according to KAU POP (package of practices). Water stress was induced by withholding irrigation for three days where the relative water content (RWC) of leaves reached 70% during the flower initiation stage. The results of the first experiment revealed that seeds primed with 3% SiO2 resulted in early flowering and first fruiting. Under water stress conditions, seeds primed with 2.5% KNO3 recorded significantly higher values for RWC (69%), cell membrane stability Index (CMSI) (42.16%), malonaldehyde (0.62 μmole ml-1), H2O2 (0.62 μmol g-1), trehalose (0.15 μmol g-1 FW), α-amylase activity (14.68 μmol maltose formed min-1 mL-1), specific leaf area (15.99 cm2 g-1) total chlorophyll content (TCC) (1.92 mg g-1), superoxide dismutase (SOD) (491.3 units mg-1 of protein), total soluble sugars (TSS) (1.53 mg/g) and total soluble protein (TSP) (1.017 mg g-1) however 3% SiO2 primed seeds recorded significantly higher values for total proline content (3.12 μmoles of proline g-1 of tissue). 136 Under control conditions, 2.5% KNO3 primed seeds recorded significantly high values for RWC (92%), trehalose (0.17 μmol g-1 FW), α-amylase activity (16.76 μmol maltose formed min-1 mL-1), specific leaf area (20.88 cm2 g-1) total chlorophyll content (TCC) (4.54 mg g-1), superoxide dismutase (SOD) (491.32 units mg-1 of protein), total soluble sugars (TSS) (3.22 mg g-1) and total soluble protein (TSP) (2.06 mg g-1) however 3% SiO2 primed seeds recorded significantly higher values for total proline content (1.31 μmoles of proline/g of tissue) and CMSI (91.0%). Under water stress conditions, capsaicin content was recorded higher in seeds primed with 2.5% KNO3 (144.6 μg g-1), and ascorbic acid was recorded the highest in seeds primed with 3% SiO2 (3.89 mg g-1). In contrast, in control, both capsaicin content (224.0 μg g-1) and ascorbic acid content (4.81 mg g-1) were recorded higher in seeds primed with 2.5% KNO3. Under water stress conditions, the yield components were higher in seeds primed with 2.5% KNO3. The plant height (60 cm), number of flowers plant-1 (24 number), number of fruits plant-1 (20 number), and fruit yield (44.29 g), were recorded as significantly higher in seeds primed with 2.5% KNO3. however, the seed yield (3.60 g) was recorded as significantly higher in seeds primed with 3% SiO2, and the number of flowers plant-1 (22 number) was found the highest in unprimed seeds. Whereas in control, 2.5% KNO3 primed seeds recorded significantly higher plant height (65.3 cm), fruit yield (90.4 g), number of fruits plant-1 (23.4), and 3% SiO2 primed seeds recorded significantly higher seed yield (4.03g). The second experiment was carried out in a factorial randomized block design (FRBD) with the first factor being stress levels and the second factor being priming using different solutions which were replicated thrice. the seeds primed with 2.5% KNO3, 3% SiO2, and unprimed seeds treatments were sown in protrays. Seedlings were transplanted to the field 35 days after sowing (DAS) and irrigation and other cultural practices were followed according to KAU POP. Water stress was induced by withholding irrigation for seven days where the (RWC) of leaves reached 70% during the flower initiation stage. During this period, physiological parameters were taken from the stress and control plants. The results revealed that seeds primed with 3% SiO2 recorded early flowering whereas seeds primed with 2.5% KNO3 recorded the first fruiting stage. Under water stress conditions, seeds primed with 2.5% KNO3 recorded significantly high values for RWC (68.16%), CMSI (46.66%), malonaldehyde (0.73 μmole ml-1), H2O2 (0.71 μmol g-1), trehalose (0.13 μmol g-1 FW), α-amylase activity (13.93 μmol maltose formed min-1 mL-1), Specific leaf area (13.47 cm2 g-1) TCC (1.93 mg g-1), SOD (520.03 units mg-1 of protein), TSS (1.55 mg g-1) and TSP (1.05 mg g-1) where 3% SiO2 primed seeds recorded significantly higher values for total proline content (3.12 μmoles of proline g-1 of tissue). For control conditions, 2.5% KNO3 primed seeds recorded significantly high values for (RWC) (79 %), trehalose (0.17 μmol g-1 FW), α-amylase activity (14.77 μmol maltose formed min-1 mL-1), Specific leaf area (18.47 cm2g-1) TCC (3.86 mg g-1), SOD (405.60 units mg-1 of protein), TSS (3.16 mg/g) and TSP (2.0 mg/g) however 3% SiO2 primed seeds recorded significantly higher values for total proline content (1.31 μmoles of proline/g of tissue) CMSI (91.16%).Under water stress conditions, capsaicin content was recorded higher in seeds primed with 2.5% KNO3 (90.5 μg g-1), and ascorbic acid was recorded the highest in seeds primed with 3% SiO2 (3.78 mg g-1). In control, capsaicin content (232.0 μg g-1) and ascorbic acid content (4.75 mg g-1) were recorded higher in seeds primed with 2.5% KNO3.Under water stress conditions, the yield components were recorded as higher in seeds primed with 2.5% KNO3 like plant height (55 cm), number of flowers plant-1 (22.8 number), number of fruits plant-1 (19 number), and the fruit yield (45.3 g), were recorded as significantly higher in seeds primed with 2.5% KNO3. The seed yield (3.16g) was recorded as significantly higher in seeds primed with 3% SiO2, under, the control condition, 2.5% KNO3 primed seeds recorded significantly higher plant height (60 cm), fruit yield (84.93 g), number of fruits plant-1 (22.4) and 3% SiO2 primed seeds recorded significantly higher seed yield (3.18 g). According to our results, seed priming with 2.5% KNO3 and 3% SiO2 enhanced the capacity of the plant to absorb water by preserving the least amount of cell damage and shielding the macromolecular structures from membrane damage, Thus, seed priming with 2.5% KNO3 and 3% SiO2 can be recommended.Item Integrated management module for sucking pest complex in chilli Capsicum annuum L.(Department of Agricultural Entomology, College of Agriculture,Vellayani, 2023-09-05) Kiran, Thomas.; Thania, Sara VargheseItem Management of calcium, magnesium and boron deficiency for enhancing yield and quality in chilli (Capsicum annuum L.)(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Padanakkad, 2022-04-28) Anjitha K.; Sailaja kumari M SThe investigation entitled ‘Management of calcium, magnesium and boron deficiency for enhancing yield and quality in chilli’ was carried out at Instructional farm, Nileshwar, College of Agriculture Padannakkad, with an objective to develop nutrient management practices for mitigating calcium, magnesium and boron deficiency and to evaluate its effect on growth, yield and quality parameters. The field experiment was carried out during December 2020 to May 2021. The experiment was carried out with chilli variety Anugraha, in randomized block design with ten treatments and three replications. Treatment combinations were T1(KAU POP + lime (based on soil test)), T2 (T1 + 125 kg gypsum per hectare), T3 (T1 + 80 kg magnesium sulphate per hectare), T4 (T1 + 125 kg gypsum per hectare + 80 kg magnesium sulphate per hectare), T5 (T1 + foliar application of borax (0.2%)), T6 (T2 + foliar application of borax (0.2%)), T7 (T3 + foliar application of borax (0.2%)), T8 (T4 + foliar application of borax (0.2%)), T9 (KAU POP + dolomite (based on soil test)) and T10 (T9 + foliar application of borax (0.2%)). Soil application of amendments were done as a single dose and foliar nutrition was given four times in a 20 days interval. Analysis of experimental results showed that various treatments showed significant effect on growth characters, fruit quality parameters as well as nutrient content in both soil and plant, over KAU POP recommendation. Significant positive effect of treatments on plant root characters and total dry matter production was observed whereas plant height and days to 50% flowering were found to be non significant. Among the treatments, maximum tap root length (13.50 cm), root volume (23.23 cm3 ), root shoot ratio (0.16) and total dry matter production (2694.65 kg ha-1 ) were recorded in T8 (KAU POP + lime application based on soil test) +125 kg gypsum per hectare + 80 kg magnesium sulphate per hectare + foliar application of borax (0.2%). Various treatments showed significant influence on yield and yield attributes. Maximum fruit weight (37.16 g) and total fruit yield (4456.79 kg ha-1 ) was also observed in T8 and in case of fruit yield, it was significantly superior to all other treatments. Combined application of gypsum, magnesium sulphate and borax were effective and maximized fruit yield. 94 Soil analysis was carried out at flowering and harvest wherein, the treatments showed significant effect on soil pH, EC, available potassium, calcium, magnesium, sulphur, iron, manganese and zinc content whereas available nitrogen, phosphorus, copper and boron were not influenced by treatments. Addition of calcium and magnesium sources significantly increased available calcium and magnesium content in soil. Among the various treatments, the highest available calcium was recorded in T8 and was on par with T2, T6 and T4 at flowering. Highest available magnesium content was recorded in T9 and T10 at flowering and harvest respectively. Analysis of Index leaves at flowering and total plant analysis at harvest were carried out and it was found that plant nutrient content was significantly influenced by treatments. Significant effect of various treatments on plant nutrients except nitrogen and phosphorus was observed. Foliar application of borax significantly improved boron content in plants. Fruit quality parameters such as capsaicin, oleoresin, ascorbic acid and shelf life and total nutrient content were analysed and results showed significant positive response to treatments. Analysis of nutrient content in fruits showed that primary nutrients mainly, nitrogen and potassium, secondary nutrients and micronutrients in fruits were significantly influenced by various treatments. The treatment, T8 (KAU POP + lime based on soil test) +125 kg gypsum per hectare + 80 kg magnesium sulphate per hectare + foliar application of borax (0.2%)) recorded highest capsaicin (0.352 %), oleoresin (11.00 %), ascorbic acid (96.83 mg 100 g-1 ) and maximum shelf life (13.66 days) in chilli. The results obtained from the experiment revealed the significant influence of soil amendments over KAU POP recommendation and it can be concluded that combined application of gypsum, magnesium sulphate and borax was effective for increasing fruit yield and quality in chilli.Item Non-chemical weed management in chilli (Capsicum annuum L.)(Department of Agronomy, College of Agriculture, Vellanikkara, 2021) Fasna P; Meera V MenonOne of the major problems in any crop production system is weed infestation which causes reduction in both the yield and quality of produce. Although the use of herbicides provides effective and sustained weed control, it is not a preferred option because of environmental concerns. This is particularly true in the case of vegetables, some of which are consumed either partially cooked or raw. The research programme entitled ‘Non-chemical weed management in chilli (Capsicum annuum L.)’ was carried out with the objective of evaluation of non-chemical methods of weed management in chilli. The experiment was conducted at the Department of Agronomy, College of Agriculture, Vellanikkara from June 2020 to September 2020. The field was infested with broad leaf weeds, grasses and sedges. Randomized block design used for laying out the experiment, with seven treatments and three replications. The treatments were, T1: stale seed bed for 14 days followed by shallow digging and planting of chilli, followed by two hand weedings at 30 DAT and 60 DAT, T2: stale seed bed for 14 days followed by shallow digging and planting of chilli, followed by one hand weeding at 45 DAT, T3: black polythene mulch (30 microns), T4: straw mulch at 7.5 t/ha applied twice, at planting and one month after planting, T5: straw mulch at 7.5 t/ha applied twice, at planting and one month after planting followed by one hand weeding at 60 DAT, T6: hand weeding at 30 and 60 DAT and T7: unweeded control. Black polythene mulch (T3) recorded highest weed control efficiency and lowest weed density, weed dry matter production and weed index, whereas straw mulch when applied alone (T4) and when followed by one hand weeding (T5) were the next best treatments with high weed control efficiency and low weed index. The treatments hand weeding (T6), stale seed bed when followed by two hand weedings (T1) and one hand weeding (T2) were not effective in controlling weeds. The lowest weed control efficiency and the highest weed index values were recorded for the unweeded control (T7) at all stages of observation. Various weed management practices had significant effect on growth and yield parameters of chilli. At all stages of observation, the plant height of chilli in polythene mulching (T3) was found to be the greatest followed by straw mulching when done alone (T4) and when followed by one hand weeding (T5). Unweeded control (T7) had the lowest values. Chilli plants in polythene mulching (T3) recorded the highest number of fruits per plant (218) and fruit yield (22.44 t/ha), followed by straw mulching both when done alone (T4) (182 nos. and 18.89 t/ha respectively) and when followed by one hand weeding (T5) (177 nos. and 18.38 t/ha respectively). Hand weeding (T6) and stale seed bed when followed by two hand weedings (T1) recorded lower yields than straw mulching. Unweeded control (T7) recorded lowest values for fruit length, fruit girth, fruit weight, number of fruits per plant and fruit yield. The soil physico-chemical characteristics pH, EC, organic carbon, and available N, P and K were influenced by different weed management practices. The organic carbon content in soil was highest in polythene mulching (T3) at 60 DAT (1.45 %) and after the final harvest (1.49 %). At both stages of observation, straw mulching (T4) had highest values of available P (77 and 79 kg/ha respectively) and K (414 and 408 kg/ha respectively), whereas available N was found higher in black polythene mulch (T3) at 60 DAT (246 kg/ha) and in stale seed bed followed by one hand weeding (T2) after the final harvest (239 kg/ha). Considering the economics of cultivation, black polythene mulching (T3) recorded highest gross returns (Rs.22.44 lakhs/ha), net returns (Rs. 9.94 lakhs/ha) and B:C ratio (1.84) and was followed by straw mulching when done alone (T4) and when followed by a hand weeding (T5). Black polythene mulching was thus identified as the best non-chemical weed management technique in chilli, having highest weed control efficiency leading to enhanced growth and yield parameters and highest net returns and B:C ratio. Straw mulching when done alone or when followed by one hand weeding were the next best treatments with respect to weed control efficiency, growth, yield and net returns of chilli.